Start Trainer, then game or vice versa. Either alt-tab and choose options or press the hotkey ingame

HotKey/Option

F1 Unlimited Stat points - Gives you unlimited stat points during hero creation up to the class maximum
F2 Unlimited Money - Money never decreases, all units/buildings/improvements are free
F3 Unlimited unit creation - Command points never increase when training units- train as many units as you want
F4 Unlimited power points - Power points increase when you purchase a power
(just purchase the power, choose APPLY, and you will notice power points were ADDED instead of subtracted)